A Fog Based Hand Sanitization System with Hand Surface Contamination

One of the most reliable ways to hinder the transmission of infectious diseases is proper hand hygiene. However, conventional hand sanitizer dispensers, whether manual pumps or touchless automatic sensors, have no means of checking if a user's hands are genuinely contaminated or have been adequately cleaned after use. This limitation makes the system less reliable, reduces user confidence, and increases the potential for hygiene errors. To address this gap, this thesis presents the design, implementation, and evaluation of HygioFog, an intelligent, two-stage hand sanitization system. HygioFog integrates a novel contamination detection mechanism with an efficient, fog-based sanitizer delivery system. The system first employs Ultraviolet (UV-A) fluorescence imaging to visibly assess and confirm the presence of contaminants on the user's hands. If contamination is detected, the system automatically deploys an ultrasonic fogger that dispenses a fine mist of sanitizer, ensuring total coverage of the hand surface, including hard-to-reach areas. The entire process is contactless and microprocessor-controlled, with real-time feedback provided to the user via an LCD display.